Smooth cordgrass named &#39;LA11-103&#39;

ABSTRACT

A new variety of smooth cordgrass identified as ‘LA11-103’ is disclosed as being genetically different from ‘Vermilion’, ‘LA11-101’, and ‘LA11-102’, as having rapid establishment and growth in natural brackish and saline marsh environments, and excellent seed set and germination.

The development of this invention was partially funded with Hatch Act Formula Funds (Project number LAB93864) and through grants from the United States Department of Agriculture's National Institute of Food and Agriculture (Agreement numbers: 2010-34396-21191, 2009-34396-20051, 2008-34396-19316, 2006-34396-17624, 2005-34396-16498). The Government may have certain rights in this invention.

This invention pertains to a new and distinct variety of smooth cordgrass.

BACKGROUND OF THE INVENTION

Smooth cordgrass (Spartina alterniflora Loisel.) is a perennial grass native to intertidal saline marshes along the Atlantic and Gulf of Mexico coasts in the United States. It is used in numerous restoration projects to decrease coastal erosion. In Louisiana, one smooth cordgrass variety, ‘Vermilion’, is used extensively. The widespread use of a single variety reduces genetic variation, thus reducing the ability to adapt to environmental changes. ‘LA11-103’, along with ‘LA11-101’ and ‘LA11-102’ were invented to provide genetically diverse smooth cordgrass varieties for northern Gulf of Mexico restoration projects.

Smooth cordgrass seeds were collected from one hundred twenty-six (126) smooth cordgrass populations throughout Louisiana in 1998. Preliminary work, which preceded this invention, evaluated smooth cordgrass plant survival and vigor in natural marsh environments and freshwater production ponds (Ryan, 2003. http://utils.louislibraries.org/cgi-bin/lz0050.x?sitecode=LALUelib?http://etd.lsu.edu/docs/available/etd-1110103-133154/ and Ryan et al., 2007. J. Aquat. Plant Manage. 45:90). In the preliminary work, no efforts were made to asexually reproduce ‘LA11-103’ for any purpose other than to provide plant material for plant performance evaluations. The new smooth cordgrass varieties (‘LA11-101’, ‘LA11-102’, ‘LA11-103’) were designated as varieties and reproduced asexually beginning in 2010. ‘LA11-103’ has a unique and stable genotype, as determined by molecular marker profiles.

BRIEF SUMMARY OF INVENTION Genus and Species Name

‘LA11-103’ is a new smooth cordgrass (Spartina alterniflora Loisel.) variety that is genetically different from ‘Vermilion’ and two additional new smooth cordgrass varieties, ‘LA11-101’ and ‘LA11-102’. Genetic diversity was determined using thirteen molecular markers. ‘LA11-103’ is more vigorous one month after transplant than ‘Vermilion’ and produces more seeds that germinates than ‘Vermilion’. ‘LA11-103’ is recommended for brackish and saline marsh restoration projects in the northern Gulf of Mexico, especially Louisiana, where genetically different smooth cordgrass varieties that rapidly establish and produce viable seeds are desired.

Variety Denomination

This new and distinct cordgrass variety, identified as ‘LA11-103’, is characterized by its unique genetic profile, as determined by thirteen (13) molecular markers, ability to recover quickly in natural environments, and high viable seed yields.

DETAILED BOTANICAL DESCRIPTION

‘LA11-103’ was developed from seed collected from smooth cordgrass plants growing along the Barataria Waterway in Jefferson Parish La. (29° 34′ 33.90″ N.; 90° 3′ 24.32″ W.) in December of 1998. Collected seeds were germinated in a greenhouse at Baton Rouge, La. This population was selected in a phenotypic selection program because of high seed germination rates, seedling survival, and seedling vigor. The twenty (20) most vigorous seedlings from this population were selected in a second selection cycle and evaluated at Baton Rouge, La. In 1999, ‘LA11-103’, along with thirty-nine (39) additional genotypes, was selected in a third selection cycle. To provide plant material for continued experimental evaluations, rhizomes and stems of ‘LA11-103’ were harvested from the experimental plot at Baton Rouge and planted into containers in controlled greenhouses. This asexual reproduction was used solely to multiply the experimental line for evaluation, and not for the asexual reproduction of the variety.

‘LA11-103’ and thirty-nine (39) additional genotypes were evaluated in experiments at Baton Rouge and Grand Terre, La., from 2000-2001. ‘LA11-103’ and seven (7) genotypes were selected in the fourth selection cycle. In 2002, rhizomes and stems of ‘LA11-102’ were harvested from experimental plots at Baton Rouge and planted into containers in controlled greenhouses. This asexual reproduction was used solely to provide material for continued experimental evaluations.

Experimental evaluations were continued from 2005-2009 at seven sites. In 2010, ‘LA11-103’ was identified as a superior cultivar and one hundred (100) single stems with rhizomes, which were verified using molecular markers to be genetically identical, were used to asexually propagate the variety ‘LA11-103’ in Plaquemines Parish, Louisiana. In 2011, rhizome and stem material were harvested and moved to Baton Rouge where asexual reproduction of rhizomes and stems has continued.

Variation in plant appearance can be caused by production conditions and does not reflect genetic differences. ‘LA11-103’ is genetically identical and stable when produced from rhizome material. ‘LA11-103’ can be definitely identified from ‘Vermilion’ based upon fragment size differences at ten (10) molecular markers, and from ‘LA11-101’ and ‘LA11-102’ using nine (9) molecular markers (Table 1).

TABLE 1 LA11-103 Vermilion LA11-101 LA11-102 Primer^(†) Fragment Size (bp) ESSR35 200 180 190 190 ESSR58 400 400 400 420 ESSR64 300 300 310 310 ESSR21 210 215 215 215 ESSR29 200 188 188 188 ESSR66 140 140 145 145 ESSR69 390 410 410 390 SPAR4 210 190 210 210 SPAR7 295 280 295 295 SPAR8 200 180 185 185 SPAR11 280 275 285 285 SPAR27 190 200 190 190 SPAR5 263 260 265 265 ^(†)ESSR sequences (Baisakh et al., 2009. Aquat. Bot 91:262; SPAR sequences Blum et al., 2004. Mol. Ecol. Notes 4: 39).

Explanation of Tests Conducted

Preliminary Field Trials:

‘LA11-103’ was selected from a preliminary field trial in which 400 plants were evaluated for performance in a freshwater production pond, Baton Rouge, La., in February 2000. ‘LA11-103’ was included in replicated trials from 2000 to 2009 in thirteen (13) environments to evaluate its performance and release potential.

Advanced Field Trials:

Advanced field trials were completed at freshwater ponds, Baton Rouge, La., and on a created marsh, Grand Terre, La., in 2001. The average plant height, spread, rust rating (Puccinia sparganiodes), and plant vigor were calculated based upon measurements completed every two (2) weeks starting eight (8) months after transplant and ending twelve (12) months after transplant for Baton Rouge and from three (3) to five (5) months after transplant for Grand Terre. Plant height was measured from the soil surface to the uppermost leaf tip of the plant. Plant spread was calculated by measuring the linear growth of each plant on two (2) perpendicular axes. Rust rating was measured with a 0-10 scale where 0 was no rust visible and 10 was rust covering all above-ground portions of the plant. Plant vigor was measured with a 0-10 scale where 0 was a dead plant and 10 was an extremely vigorous plant.

Elite Field Trials:

Elite field trials were completed on a created marsh at Grand Terre; on man-made marsh terraces, Cameron Parish, La., in 2003; and in freshwater rice production fields, Rayne, La., in 2005 and 2006. Plant vigor was measured at Grand Terre and Cameron Parish approximately six (6) months after transplant. Plant vigor, rust rating, plant spread, plant height, and the total number of stems per plot were measured at Rayne in 2005 and 2006, approximately five (5) months after transplant. Percent seed set and seed germination were also determined at Rayne in 2005. Percent seed set was determined on ten (10) randomly selected panicles harvested the first week of November. Each panicle was individually bagged with 4.5 cm×40 cm cellulose tubes to collect seeds that shattered prior to harvest in early December. The total number of florets and the number of florets containing seeds (filled florets) were determined using a fluorescent light box. Percent seed set was calculated as follows: [(number of filled seed/total number of florets)* 100]. Percent seed germination was determined with five (5) replicates of one hundred (100) seeds. Seeds were placed into Petri dishes containing a #4 filter paper and 8 ml of 0.05% 200 g/L carboxin and 200 g/L thiram solution. Petri dishes were sealed with parafilm to minimize evaporation and placed in an incubator at 24-26° C. and 16/8 hr light/dark for six (6) weeks and percent seed germination was calculated.

Supreme Field Trials:

Supreme field trials were evaluated at a man-made marsh terrace, Cameron Parish, La., in 2008; two (2) eroded marsh areas, Grand Chenier, La., in 2008 and 2009; and two (2) freshwater rice production fields, Rayne, La. in 2008 and 2009. Plant vigor was measured at Cameron Parish one (1) month after transplant. Plant vigor and number of stems were measured at Cameron Parish one (1) year after transplant. Plant vigor, rust rating, plant spread, plant height, and number of stems per plot were measured approximately six (6) months after transplant at Grand Chenier in 2008 and 2009. Plant vigor, rust rating, plant spread, plant height, number of stems, percent seed set, and percent seed germination were measured at Rayne in 2008 and 2009, approximately six (6) months after transplant.

EXAMPLE 1 Advanced Field Trials

In advanced field trials, ‘LA11-103’ was as vigorous, spread as far, and had a similar rust rating and plant height as ‘Vermilion’ (Table 2).

TABLE 2 Baton Rouge, LA Grand Terre Island, LA Variety Height^(†) (cm) Spread (m²) Rust^(‡) Vigor^(§) Height (cm) Spread (m²) Rust Vigor ‘LA11-103’ 121.0 a 2.2 a 3.4 a 7.5 a 87.0 a 1.3 a 1.8 a 6.3 a ‘Vermilion’ 140.0 a 1.0 a 3.5 a 7.2 a 99.0 a 1.2 a 2.4 a 6.5 a ^(†)Means within the same column that are followed by different letters are significantly different (t test, p < 0.05). ^(‡)Rust rating was visually estimated on a scale of 0-10 (0 = no rust visible; 10 = rust covering all above-ground portions of the plant). ^(§)Vigor was visually estimated on a scale of 0-10 (0 = dead; 10 = excellent).

EXAMPLE 2 Elite Field Trials

In elite field trials ‘LA11-103’ was as vigorous as ‘Vermilion’ at Cameron Parish, Grand Terre, and Rayne in 2006 (Table 3). It was less vigorous than ‘Vermilion’ at Rayne in 2005. ‘LA11-103’ also spread as far and had a similar rust reaction as ‘Vermilion’ (Table 3). ‘LA11-103’ had higher seed set and seed germination than ‘Vermilion’ and was shorter and had less stems per plot than ‘Vermilion’ in freshwater rice production fields (Table 3).

TABLE 3 Number of Seed Set Seed Germination Variety Vigor^(†) Rust^(‡) Spread (m²) Height (cm) Stems (%) (%) Cameron Parish, 2003 ‘LA11-103’ 7.8 a — — — — — — ‘Vermilion’ 8.8 a — — — — — — Grand Terre, 2003 ‘LA11-103’ 5.6 a — — — — — — ‘Vermilion’ 7.8 a — — — — — — Rayne, 2005 ‘LA11-103’ 8.3 b 2.3 a 1.5 a 146.0 b  83.7 b 55.0 a 76.0 a ‘Vermilion’ 9.7 a 2.7 a 2.5 a 209.3 a 138.3 a 20.7 b 35.3 b Rayne, 2006 ‘LA11-103’ 8.0 a 3.3 a 1.4 a 153.3 b  82.3 b — — ‘Vermilion’ 9.0 a 2.3 a 2.6 a 218.0 a 121.7 a — — ^(†)Vigor was visually estimated on a scale of 0-10 (0 = dead; 10 = excellent); Means within the same column and location followed by different letters are significantly different (t test, p < 0.05). ^(‡)Rust rating was visually estimated on a scale of 0-10 (0 = no rust visible; 10 = rust covering all above-ground portions of the plant).

EXAMPLE 3 Supreme Field Trials

In supreme field trials, ‘LA11-103’ was more vigorous than ‘Vermilion’ one month after transplant on man-made marsh terraces in Cameron Parish (Table 4). ‘LA11-103’ was as vigorous, spread as far, and had approximately an equal number of stems per plot and rust rating as ‘Vermilion’ at the remaining locations (Table 4). ‘LA11-103’ had a higher seed set and germination rate than ‘Vermilion’ (Table 4). It was also shorter than ‘Vermilion’ in supreme field trials (Table 4).

TABLE 4 Number of Seed Set Seed Germination Variety Vigor^(†) Rust^(‡) Spread (m²) Height (cm) Stems (%) (%) Cameron Parish, 2008^(§) ‘LA11-103’  4.7 a — — — — — — ‘Vermilion’  1.0 b — — — — — — Cameron Parish, 2009^(§) ‘LA11-103’  4.3 a — — —  11.0 a — — ‘Vermilion’  4.7 a — — —  16.0 a — — Grand Chenier, 2008 ‘LA11-103’  7.3 a 3.3 a 1.5 a  99.0 b  78.0 a — — ‘Vermilion’ 10.0 a 1.3 a 2.6 a 164.0 a  92.7 a — — Grand Chenier, 2009 ‘LA11-103’  8.0 a 3.0 a 1.8 a 101.0 b  71.0 a — — ‘Vermilion’  9.3 a 1.0 a 2.5 a 153.0 a  92.3 a — — Rayne, 2008 ‘LA11-103’  7.0 a 2.7 a 1.1 a 123.0 b  63.0 a 63.0 a 76.3 a ‘Vermilion’  8.7 a 2.7 a 2.6 a 209.0 a 102.7 a 27.3 b 38.0 b Rayne, 2009 ‘LA11-103’  7.0 a — 0.9 a 153.0 b  66.0 a 58.3 a 72.0 a ‘Vermilion’  9.3 a — 1.8 a 188.0 a 107.0 a 21.3 b 40.0 b ^(†)Vigor was visually estimated on a scale of 0-10 (0 = dead; 10 = excellent); Means within the same column and location followed by different letters are significantly different (t test, p < 0.05). ^(‡)Rust rating was visually estimated on a scale of 0-10 (0 = no rust visible; 10 = rust covering all above-ground portions of the plant). ^(§)Cameron Parish was established in 2008 and evaluated in 2008 one (1) month after transplant and in 2009 one (1) year after transplant. 

We claim:
 1. A new and distinct variety of Spartina alterniflora named ‘LA11-103’ as described and illustrated in the specification herein. 